Spatial audio downmixing

ABSTRACT

Channels of audio data in a spatial audio object are associated with any one or more of a direction and a location of one or more recorded sounds, which channels are to be reproduced as spatial sound. A visualized spatial sound object represents a snapshot/thumbnail of the spatial sound. To preview the spatial sound (by experiencing its snapshot or thumbnail), a user manipulates the orientation of the visualized spatial sound object, and a weighted downmix of the channels is rendered for output as a spatial preview sound, e.g., a single output audio signal is provided to a spatial audio renderer; one or more of the channels that are oriented toward the user are emphasized in the preview sound, more than channels that are oriented away from the user. Other aspects are also described and claimed.

This application is a continuation of pending U.S. application Ser. No.17/474,455 file Sep. 14, 2021, which is a continuation of U.S.application Ser. No. 16/645,429 filed Mar. 6, 2020, now U.S. Pat. No.11,128,977 issued Sep. 21, 2021, which is a 371 National Stage Entry ofInternational Application No. PCT/US2018/052960 filed Sep. 26, 2018,which claims the benefit of the earlier filing date of U.S. ProvisionalApplication No. 62/566,228 filed Sep. 29, 2017.

TECHNICAL FIELD

The technical field relates generally to computerized data processingsystems and methods for audio processing, and in particular to spatialaudio processing.

BACKGROUND

Producing three-dimensional (3D) sound effects in augmented reality(AR), virtual reality (VR), and mixed reality (MR) applications(encompassed by the term “simulated reality” or SR, as used here) iscommonly used to enhance media content. Examples of spatial audioformats designed to produce 3D sound include MPEG-H (Moving PictureExperts Group) 3D Audio standards, HOA (Higher-order Ambisonics) spatialaudio techniques, and DOLBY ATMOS surround sound technology.

For example, sound designers add 3D sound effects by manipulating soundscontained in spatial audio objects to enhance a scene in an SRapplication, where the sounds are ambient sounds and/or discrete soundsthat can be virtually located for playback by the spatial audio systemanywhere in the virtual 3D space created by the SR application.

SUMMARY

Embodiments of spatial audio downmixing as herein described enableaugmented reality/virtual reality/mixed reality (SR) applicationdevelopers, and listeners in an SR experience created by the SRapplication, to preview a sound from audio data in which the sound hasbeen encoded and that is capable of being composed into the SRapplication. In one embodiment the audio data in which the sound isrecorded or encoded is stored as a spatial audio object that preservesspatial characteristics of one or more recorded sounds. In oneembodiment, the spatial audio object contains several channels of audiodata representing the one or more recorded sounds, each channel beingassociated with any one or more of a direction and a location(distance), e.g., of a source of the recorded sound. Note that there maybe two or more of such channels that are associated with a givendirection or location, e.g., a multi-channel microphone pickup. In otherembodiments, the spatial audio object contains multiple channels of anambisonics format (spherical harmonics format) representation of a soundfield where in that case each channel is associated with a respectivespatial distribution, e.g., B-format WXYZ channels. To then enable theaural preview, the audio channels are subjected to a spatial audiodownmixing operation.

In one embodiment, spatial audio downmixing includes generating avisualized spatial sound object (or more generally, presenting avisualization of the spatial audio object) to represent or enable a userto experience an aural snapshot of the plurality of channels of audiodata, and presenting the visualized spatial sound object in a userinterface, e.g., a graphical user interface. For example, the visualizedspatial sound object can be a virtual globe (e.g., a topological sphere,a cube, a bubble, a polyhedron) or other two or three-dimensionalvirtual object that can represent multiple channels of sound emanating,from a shared location in space, in multiple directions. More generally,each of the channels may be associated with a portion of the visualrepresentation based on that channel's respective direction or location.

In one embodiment, a graphical user interface is configured to enableits user to manipulate a relative orientation between the visualizedspatial sound object and a listening position (e.g., maintaining thelistening position fixed while turning the visualized spatial soundobject, or moving the listening position around while not turning thesound object). The preview process includes weighting each channel ofthe plurality of channels of audio data based on the orientation of thevisualized spatial sound object relative to the listening position(e.g., where the user is located). In one instance, the preview processis orienting each of the weighted channels in a direction that isopposite to an original orientation of the respective weighted channel,and downmixing the reoriented weighted channels. A channel that isvisually oriented toward a predetermined object, such as one thatrepresents a location of the user (e.g., facing toward a viewingposition or viewing orientation of the user) may be weighted more thanchannels oriented away from the predetermined object (e.g., away fromthe user or viewing location). The weighted channels are downmixed intoone or more virtual speaker driver signals, and these will be convertedby a spatial audio processor to drive two or more real speakers (e.g., aleft and right headphone pair) which present the sound of the downmixedweighted channels, as an aural preview of the spatial audio object. Inthis manner the visualized spatial sound object functions as a containerof snapshots or thumbnails of the recorded sounds in the spatial audioobject.

The recorded sounds can be explored or previewed one at a time byorienting the visualized spatial sound object until a graphical portionof the object (that represents a particular sound of interest) directlyfaces or is in the direction of the user. In some instance, two or moresounds can be previewed simultaneously as a blend or mix, in response tothe visualized spatial sound object being oriented so that parts of twoor more portions (corresponding to those two or more sounds) directlyface the user. The object may contain different ambient sounds ofreal-world environments, e.g., one or more channels may be the soundrecorded at a particular beach (e.g., a single microphone channelrecording, a multi-channel recording), another channel may be the soundrecorded in an alpine forest, and another channel may be the soundrecorded in a city. The object may also contain a channel that is asynthesized sound of a virtual 3D environment.

The preview process continues with the audio channels of the objectbeing weighted according to the graphical portion that is facing theuser, and then downmixed into one or more audio signals that drive oneor more acoustic output transducers, respectively, e.g., earpiecespeakers, loudspeakers, through which the user hears the previewed sound(and not any other sounds that are also contained in the object.)

In one embodiment, generating the visualized spatial sound object torepresent a snapshot of the plurality of channels of audio data includesassigning each channel of the plurality of channels of audio data to ashared location in space and orienting each assigned channel to emit(virtual sound) outward from the shared location. For example, eachassigned channel is oriented to emit virtual sound, using the assignedchannel, outward from the shared location in a direction that isopposite to that from which a predominant recorded sound in the assignedchannel originated, to form a virtual globe of the audio data. Arespective image is added to the visualized spatial sound object foreach oriented channel, wherein the respective image is that of a sourceof the predominant recorded sound in the oriented channel. This resultsin the formation of a virtual globe (or other multi-dimensional virtualrepresentation) of sounds recorded in the audio data, where eachassigned channel is oriented to emit in a direction that is opposite tothat from which predominant recorded sound in the assigned channeloriginated.

In one embodiment, generating the visualized spatial sound objectincludes adding an image to the visualized spatial sound object for eachof the oriented channels of the visualized spatial sound object. Theimage may be a still picture, or it may be part of a video sequence, andmay be added to the visualized sound object for each of orientedchannels. The image may be that of a source of the predominant recordedsound in the oriented channel, or of a scene associated with therecorded sound, such as a tree for a forest sound, a car for a citysound, a wave for a beach sound, a video of crashing water in a waterfall, a video of crashing waves at a beach, a video of trees moving inthe wind, and the like. Adding the image causes the image to bedisplayed on a portion of the surface of the visualized spatial soundobject that corresponds to the outward direction of the oriented channelthat is associated with that portion. The images may cover the surfaceof the virtual globe like continents on Earth that are visible fromouter space; they function as a visual aid for previewing sounds. Insome embodiments, however, previewing a sound can be accomplishedwithout the image as a visual aid.

In one embodiment, presenting the visualized spatial sound object isperformed in a user interface that is configured to enable a user tomanipulate (e.g., using a finger on a touch screen, a mouse input tomove a cursor on a screen, or by speaking a command) an orientation ofthe visualized spatial sound object. An image of the visualized spatialsound object can be displayed for example on a flat display screen, in a2D or in a 3D display mode. The user interface may be configured torotate the displayed visualized spatial sound object about differentaxes, in accordance with the received user input and in real-time, ormore generally orient the visualized spatial sound object relative tothe user, so that a different portion of the visualized spatial soundobject is visible to the user. In one embodiment, the portion of thevisualized spatial sound object that is visible to the user includes theimage that was added to the object and associated with the one or moreof the oriented channels. Thus, one portion at a time may be facing ordirected towards the user so that the sounds contained in the object arepreviewed one at a time as the orientation of the object is changing.

In one embodiment, weighting each channel of the plurality of channelsof audio data based on the orientation of the visualized spatial soundobject is performed continuously (repeatedly and updated in real-timebased on the current orientation.) This may be based on which portionsof the visualized spatial sound object (and therefore which channelsassociated with that portion) are oriented toward the user and whichportions are oriented away from the user. The sounds may thus share acommon location from which their virtual sources, respectively, emitsound outwardly. The snapshot or thumbnail of the sounds can be exploredand previewed by orienting the visualized spatial sound object to asound of interest, such as a particular sound in the ambient sound of areal-world environment like a beach, alpine forest or city sound, or aparticular sound in the synthesized sound of a virtual 3D environment.

In one embodiment, previewing the sound in the SR environment dependsupon how the sound represented by the spatial audio object is simulatedin a spatial audio/spatial sound playback system, including singlelistener playback systems that use binaural rendering (e.g., throughheadphones worn by the user who wishes to preview sound through theheadphones), loudspeakers, or a combination of headphones andloudspeakers. The spatial audio downmixing may also support a variety ofsound sources and audio encodings (for reproducing sound to simulatespatial audio in sound playback systems).

The spatial audio object contains audio data encoding sounds, includingany one or more of i) a monaural recording of an individual sound, ii) amulti-channel recording of a sound environment including any one of arecording produced using an array of microphones, a recorded mix ofmultiple sound sources including a mix of multiple discrete soundsrecorded using one or more microphones, or a recording that preservesspatial characteristics of recorded sound, and iii) synthesized audiodata for producing one or more sounds or iv) a recording in ambisonicformat.

The audio data in which the sound is encoded (for preview by the user)may be based on characteristics that are associated with how the soundwas captured, including any one or more of i) a location of the soundincluding a discrete location of the sound or a location encoded usingthe aforementioned Higher Order Ambisonic (HOA) format, ii) at least onedirectivity of the sound per channel of audio data, the directivityrepresenting any one of a width, shape or a mathematical function usedto convey directivity of the sound, iii) an orientation of the sound,including an orientation per channel of audio data, iv) an originalsound pressure level (SPL) of the sound, including a distance at whichthe SPL was captured, v) a size or shape of the sound expressed as avolumetric size or shape of sound, e.g., as a polygonal mesh, and vi) aplayback rate for the sound, including a global playback rate for allchannels of the audio data.

In one embodiment, the plurality of characteristics associated with howthe sound was encoded in the audio data includes a description of anyone or more recording systems used to capture the sound, including adescription of an array of microphones used to record the sound.

The methods described here can be performed by a data processing systemhaving sound output capability, said to preview sound in an SRenvironment, in accordance with the spatial audio downmixing techniquesdescribed here. The data processing system may be a server computer, adesktop computer or other data processing system in which one or moreprocessors (generically referred to here as “a processor”) execute acomputer program or instructions stored in one or more non-transitorymachine readable media that cause the system to perform the one or moremethods described herein.

The above summary does not include an exhaustive list of all embodimentsin this disclosure. All systems and methods can be practiced from allsuitable combinations of the various aspects and embodiments summarizedabove, and also those disclosed in the Detailed Description below.

BRIEF DESCRIPTION OF THE DRAWINGS

Several aspects of the disclosure here are illustrated by way of exampleand not by way of limitation in the figures of the accompanying drawingsin which like references indicate similar elements. It should be notedthat references to “an” or “one” aspect in this disclosure are notnecessarily to the same aspect, and they mean at least one. Also, in theinterest of conciseness and reducing the total number of figures, agiven figure may be used to illustrate the features of more than oneaspect of the disclosure, and not all elements in the figure may berequired for a given aspect.

FIG. 1 is a block diagram illustrating an overview of spatial sound usein SR environments in accordance with one or more embodiments describedherein.

FIG. 2 and FIG. 3A, FIG. 3B and FIG. 3C are block diagrams illustratingspatial sound preview examples in accordance with one or moreembodiments described herein.

FIG. 4 is a block diagram illustrating spatial sound downmixingprocesses for use in previewing sound in SR environments in accordancewith one or more embodiments described herein.

DETAILED DESCRIPTION

Various embodiments or aspects will be described with reference todetails discussed below, and the accompanying drawings will illustratethe various embodiments. The following description and drawings areillustrative and are not to be construed as limiting. Numerous specificdetails are described to provide a thorough understanding of variousembodiments. However, in certain instances, well-known or conventionaldetails are not described in order to provide a concise discussion ofembodiments.

Reference in the specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin conjunction with the embodiment can be included in at least oneembodiment. The appearances of the phrase “in one embodiment” in variousplaces in the specification do not necessarily all refer to the sameembodiment. The processes depicted in the figures that follow areperformed by processing logic that comprises hardware (e.g., circuitry,dedicated logic, etc.), software, or a combination of both. Although theprocesses are described below in terms of some sequential operations, itshould be appreciated that some of the operations described may beperformed in a different order. Moreover, some operations may beperformed in parallel rather than sequentially.

Physical Setting

A physical setting refers to a world that individuals can sense and/orwith which individuals can interact without assistance of electronicsystems. Physical settings (e.g., a physical forest) include physicalelements (e.g., physical trees, physical structures, and physicalanimals). Individuals can directly interact with and/or sense thephysical setting, such as through touch, sight, smell, hearing, andtaste.

Simulated Reality

In contrast, a simulated reality (SR) setting refers to an entirely orpartly computer-created setting that individuals can sense and/or withwhich individuals can interact via an electronic system. In SR, a subsetof an individual's movements is monitored, and, responsive thereto, oneor more attributes of one or more virtual objects in the SR setting ischanged in a manner that conforms with one or more physical laws. Forexample, a SR system may detect an individual walking a few pacesforward and, responsive thereto, adjust graphics and audio presented tothe individual in a manner similar to how such scenery and sounds wouldchange in a physical setting. Modifications to attribute(s) of virtualobject(s) in a SR setting also may be made responsive to representationsof movement (e.g., audio instructions).

An individual may interact with and/or sense a SR object using any oneof his senses, including touch, smell, sight, taste, and sound. Forexample, an individual may interact with and/or sense aural objects thatcreate a multi-dimensional (e.g., three dimensional) or spatial auralsetting, and/or enable aural transparency. Multi-dimensional or spatialaural settings provide an individual with a perception of discrete auralsources in multi-dimensional space. Aural transparency selectivelyincorporates sounds from the physical setting, either with or withoutcomputer-created audio. In some SR settings, an individual may interactwith and/or sense only aural objects.

Virtual Reality

One example of SR is virtual reality (VR). A VR setting refers to asimulated setting that is designed only to include computer-createdsensory inputs for at least one of the senses. A VR setting includesmultiple virtual objects with which an individual may interact and/orsense. An individual may interact and/or sense virtual objects in the VRsetting through a simulation of a subset of the individual's actionswithin the computer-created setting, and/or through a simulation of theindividual or his presence within the computer-created setting.

Mixed Reality

Another example of SR is mixed reality (MR). A MR setting refers to asimulated setting that is designed to integrate computer-created sensoryinputs (e.g., virtual objects) with sensory inputs from the physicalsetting, or a representation thereof. On a reality spectrum, a mixedreality setting is between, and does not include, a VR setting at oneend and an entirely physical setting at the other end.

In some MR settings, computer-created sensory inputs may adapt tochanges in sensory inputs from the physical setting. Also, someelectronic systems for presenting MR settings may monitor orientationand/or location with respect to the physical setting to enableinteraction between virtual objects and real objects (which are physicalelements from the physical setting or representations thereof). Forexample, a system may monitor movements so that a virtual plant appearsstationery with respect to a physical building.

Augmented Reality

One example of mixed reality is augmented reality (AR). An AR settingrefers to a simulated setting in which at least one virtual object issuperimposed over a physical setting, or a representation thereof. Forexample, an electronic system may have an opaque display and at leastone imaging sensor for capturing images or video of the physicalsetting, which are representations of the physical setting. The systemcombines the images or video with virtual objects, and displays thecombination on the opaque display. An individual, using the system,views the physical setting indirectly via the images or video of thephysical setting, and observes the virtual objects superimposed over thephysical setting. When a system uses image sensor(s) to capture imagesof the physical setting, and presents the AR setting on the opaquedisplay using those images, the displayed images are called a videopass-through. Alternatively, an electronic system for displaying an ARsetting may have a transparent or semi-transparent display through whichan individual may view the physical setting directly. The system maydisplay virtual objects on the transparent or semi-transparent display,so that an individual, using the system, observes the virtual objectssuperimposed over the physical setting. In another example, a system maycomprise a projection system that projects virtual objects into thephysical setting. The virtual objects may be projected, for example, ona physical surface or as a holograph, so that an individual, using thesystem, observes the virtual objects superimposed over the physicalsetting.

An augmented reality setting also may refer to a simulated setting inwhich a representation of a physical setting is altered bycomputer-created sensory information. For example, a portion of arepresentation of a physical setting may be graphically altered (e.g.,enlarged), such that the altered portion may still be representative ofbut not a faithfully-reproduced version of the originally capturedimage(s). As another example, in providing video pass-through, a systemmay alter at least one of the sensor images to impose a particularviewpoint different than the viewpoint captured by the image sensor(s).As an additional example, a representation of a physical setting may bealtered by graphically obscuring or excluding portions thereof.

Augmented Virtuality

Another example of mixed reality is augmented virtuality (AV). An AVsetting refers to a simulated setting in which a computer-created orvirtual setting incorporates at least one sensory input from thephysical setting. The sensory input(s) from the physical setting may berepresentations of at least one characteristic of the physical setting.For example, a virtual object may assume a color of a physical elementcaptured by imaging sensor(s). In another example, a virtual object mayexhibit characteristics consistent with actual weather conditions in thephysical setting, as identified via imaging, weather-related sensors,and/or online weather data. In yet another example, an augmented realityforest may have virtual trees and structures, but the animals may havefeatures that are accurately reproduced from images taken of physicalanimals.

Hardware

Many electronic systems enable an individual to interact with and/orsense various SR settings. One example includes head mounted systems. Ahead mounted system may have an opaque display and speaker(s).Alternatively, a head mounted system may be designed to receive anexternal display (e.g., a smartphone). The head mounted system may haveimaging sensor(s) and/or microphones for taking images/video and/orcapturing audio of the physical setting, respectively. A head mountedsystem also may have a transparent or semi-transparent display. Thetransparent or semi-transparent display may incorporate a substratethrough which light representative of images is directed to anindividual's eyes. The display may incorporate LEDs, OLEDs, a digitallight projector, a laser scanning light source, liquid crystal onsilicon, or any combination of these technologies. The substrate throughwhich the light is transmitted may be a light waveguide, opticalcombiner, optical reflector, holographic substrate, or any combinationof these substrates. In one embodiment, the transparent orsemi-transparent display may transition selectively between an opaquestate and a transparent or semi-transparent state. In another example,the electronic system may be a projection-based system. Aprojection-based system may use retinal projection to project imagesonto an individual's retina. Alternatively, a projection system also mayproject virtual objects into a physical setting (e.g., onto a physicalsurface or as a holograph). Other examples of SR systems include headsup displays, automotive windshields with the ability to displaygraphics, windows with the ability to display graphics, lenses with theability to display graphics, headphones or earphones, speakerarrangements, input mechanisms (e.g., controllers having or not havinghaptic feedback), tablets, smartphones, and desktop or laptop computers.

FIG. 1 illustrates an overview of how sound is recorded (recording 102),and played back (playback 104) as either being experienced by an enduser (experience 106) or previewed by for example a developer (preview108), in SR environments. For example, in the recording 102, amicrophone array may be used to capture sounds from differentdirections, where what is shown is an example of six microphonescapturing ambient sound in six cardinal directions from a centralorigin, 1, 2, 3, 4, 5 and 6. To illustrate, the example here has soundsfrom a waterfall captured or recorded on one side from direction 4, andsounds from a forest captured on the opposite side from direction 2.During playback 104, these sounds are reproduced to replicate theiroriginal directionality, e.g. the waterfall at 13 a, the forest at 11 a,and a mix of the waterfall and forest at 12 a, 10 a. Other such“channels” of sound are not shown but may be produced or added atplayback 104 to enhance the original recording of the waterfall forexample, through added reflection, reverberation, and the like. Duringthe SR experience 106 of the sounds, the sounds are now directed to aparticular predefined object, e.g., representing a listener location, tosimulate how a listener would perceive the actual sound field of therecording 102. In the example shown, the listener is wearing headphonesand is positioned at the central origin, and the waterfall sound isdirected towards the listener (or originates) from the listener's right13 b and the forest sound originates from the left 11 b, with a mix ofthe forest and waterfall sounds being directed to the listener from theother directions (e.g., front 12 b, rear 10 b) that are in between orelevated from the left 11 b and right 13 b. In this example, theexperience 106 is performed by a spatial audio system that is binaurallyrendering the sounds through headphones worn by an actual listener(e.g., the end user), so that that the listener hears the originallyrecorded sounds with proper localization and immersive character (givingthe listener the impression of “being there”, e.g., facing forward or inthe direction of microphone 3, at the central origin of the recording102.)

To assist a user who is a developer or author of a SR application, aspatial sound preview process (preview 108) may be performed by acomputer, which enables the user to effectively preview a sound, apartfrom the experience 106 of the sound in the SR environment. This is alsoreferred to here as a preview mixed sound 14, for example a single audiosignal, which is produced by a spatial audio downmixing process as aweighted combination of all of the sounds captured during recording 102.This weighted combination can be user-controlled as described below indetail, by enabling the user to manipulate a visualized representationof the sounds captured during recording 102.

For example, with reference to FIG. 2 , the process in a spatial soundpreview 108 may begin with accessing a spatial sound visualizationobject 206 that is provided to a preview mixer 204 that operates toprovide the preview mixed sound 14 that is the weighted combination ofall of the sounds captured during recording 102 (and that are containedin the object 206). The spatial sound visualization object 206 can bepresented (displayed) to the user as a 3D graphical object that has twoor more “faces” or portions that have images of the available sounds (inthe object 206), respectively. Examples include a globe, a polyhedron ora topological sphere. The interface permits the user to manipulate orre-orient the 3D graphical object (of the spatial sound visualizationobject 206) such that some sounds whose respective faces or portions are“facing” the listener are weighted more than the other sounds. This isespecially useful as part of an authoring tool in an audio designapplication 210, that enables a developer (e.g., scene designers) tocompose scenes for audiovisual media, including previewing and selectingsound sources. But the spatial sound preview 108 can also be employed inan SR environment 212 to give the end user the impression that amulti-faceted graphical object that the user is holding in her hand iscontrolling the playback of a variety of sounds; each of those sounds isassociated with a respective face of the graphical object (e.g., asshown in FIG. 1 , the listener 208 has turned the graphical object sothat an image of a waterfall is “facing” the listener 208 and thistriggers playback of the waterfall sounds that are contained in theobject 206 (and which the listener 208 then hears).

With reference to FIGS. 3A-3C, these are illustrations of threedifferent instances of preview 108, where the listener 208 isconfiguring a preview sound interface 302 into three different states,respectively. The spatial sound visualization object 206 is orienteddifferently in each state, in accordance with instructions from thelistener 208, e.g. as input via a touch screen finger scroll or via amouse movement. In the case of FIG. 3A, the listener 208 has instructedthe preview sound interface 302 to orient the 3D solid graphical objectsuch that the image of a particular sound, here the forest, is orienteddirectly toward the user 208 in FIG. 3A. Similarly, when the image ofthe waterfall is oriented directly toward the user 208 as in FIG. 3B,the preview sound interface 302 responds by reproducing only thewaterfall sound (by reducing to a minimum the weights that are assignedto all other sounds in the object 206). Finally, when both the waterfalland the forest are oriented toward the user 208 as in FIG. 3C, (or aportion of the 3D graphical object that is immediately adjacent to andbetween the waterfall and the forest images is oriented directly at thelistener 208), then the preview sound interface 302 responds byreproducing both the waterfall and the forest sounds, e.g., weightingthem equally and more than all of the other sounds in the object 206. Ineach example, the preview sound mixer 204 generates the previewed sounddifferently depending on which scene predominates by being oriented atthe listener 208, e.g., forest, waterfall, or both.

FIG. 4 illustrates the spatial sound preview process in further detail.In one embodiment, a composed spatial audio object 404, such as thecombined forest/waterfall ambient sounds described in FIGS. 1-3A-3C isretrieved from a spatial audio library 402. A spatial sound preview userinterface 406 generates (operation 408) a visualized spatial soundobject 206, such as a virtual globe (e.g., sphere, bubble, cube,polyhedron, etc.) in response to a request (e.g., from the user) topreview the sound represented in the composed spatial audio object 404.In the example of FIG. 4 , the object 206 is a virtual sphere having acentral origin from which all of the spatial sounds represented by thedifferent triangles will emanate. In other words, each triangle mayrepresent a loudspeaker (acoustic output transducer) that is pointedoutward and placed at the same location (the central origin of thevirtual sphere).

In one embodiment, once the user has manipulated the visualized spatialsound object 206 as desired, the spatial sound preview user interface406 generates a virtual listener/user location 410 and a visualizedspatial sound object orientation 412 relative to the listener/user, andsends this information to the preview matrix mixer 416. In oneembodiment, the spatial sound preview user interface 406 generates theweighted source sound channels 1 . . . N 414 based on the virtuallistener/user location 410 and the visualized spatial sound objectorientation 412 relative to the listener/user.

In one embodiment, upon receipt of the listener/user location 410,orientation 412 and weighted channel information (weighted source soundchannels 414), the preview matrix mixer 416 generates a single mixedchannel of sound from a weighted downmix of the weighted source soundchannels 1, . . . N. The single mixed channel of sound is transmitted toa spatial audio render engine 418 for reproduction through a soundsystem, for the user to preview 420 the mixed sound. In one embodiment,the user can preview the mixed sound while in an SR environment, such asby previewing a portion of the SR environment, e.g. a virtual roomwithin the SR environment, presented to the user as a bubble of theroom's ambient sounds, where the bubble is the visualized spatial soundobject 206. This allows, for example, an SR listener to “peek” inside avirtual room to preview the sound emanating from the room withoutentering it. Once the SR listener enters the room, however, the previewof the sound then changes to one that envelopes the listener as itnormally would in an SR environment, e.g., as the experience 106depicted in FIG. 1 where the listening position is now “at the center”and the previewed sounds are reproduced as spatial audio according totheir assigned position in the SR application.

Returning to FIG. 4 and the preview process, in one embodiment, theweighted source sound channels 1, N 414 are weighted such that thechannels oriented toward or pointing at the user/SR listener are theloudest in the mixed sound preview 420.

The systems and methods described herein can be implemented in a varietyof different data processing systems and devices, includinggeneral-purpose computer systems, special purpose computer systems, or ahybrid of general purpose and special purpose computer systems.Exemplary data processing systems that can use any one of the methodsdescribed herein include server systems, desktop computers, laptopcomputers, embedded electronic devices, or consumer electronic devices.

It will be apparent from this description that aspects of the presentinvention may be embodied, at least in part, in software. That is, thetechniques may be carried out in a data processing system in response toits processor executing a sequence of instructions contained in astorage medium, such as a non-transitory machine-readable storage medium(e.g., DRAM or flash memory). In various embodiments, hardwiredcircuitry may be used in combination with software instructions toimplement the present invention. Example data processing systems thatcan perform the processes described above in the preview 108 include alaptop computer, a desktop computer, and a tablet computer; these mayhave access to the spatial audio library 402 which may be storedremotely in cloud storage for example.

In the foregoing specification, specific exemplary embodiments have beendescribed. It will be evident that various modifications may be made tothose embodiments without departing from the broader spirit and scopeset forth in the following claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

1-20. (canceled)
 21. A computer-implemented method for processing audio,the method comprising the following operations performed by a computer:receiving an audio object encoded to preserve spatial characteristics ofa plurality of recorded sounds, wherein the audio object comprises aplurality of channels of audio data representing the recorded sounds,each channel being associated with any one or more of a direction and alocation; presenting a visual representation of the audio object; whenturning the visual representation relative to a listening positioning,weighting each channel of the plurality of channels of audio data basedon an orientation of the visual representation relative to the listeningposition, wherein a channel associated with a portion of the visualrepresentation that is oriented toward the listening position isweighted more than a channel associated with a portion of the visualrepresentation oriented away from the listening position; and presentingsound based on the weighted plurality of channels.
 22. Thecomputer-implemented method of claim 21, wherein presenting the visualrepresentation comprises: displaying an image corresponding to a givenportion of the visual representation, the image representing apredominant recorded sound represented by one or more of the pluralityof channels, which are associated with the given portion of the visualrepresentation.
 23. The computer-implemented method of claim 21, furthercomprising orienting each of the weighted plurality of channels in adirection that is different than an original orientation of the channel;and downmixing the reoriented weighted plurality of channels one or morevirtual speaker signals.
 24. The computer-implemented method of claim21, wherein presenting sound based on the weighted channels simulatesthe sound as originating from a location corresponding to the visualrepresentation.
 25. The computer-implemented method of claim 21, furthercomprising: receiving a user input to re-orient the visualrepresentation relative to the listening position so that a differentportion of the visual representation is visible from the listeningposition.
 26. The computer-implemented method of claim 25, wherein thedifferent portion of the visual representation includes an imagerepresenting a predominant recorded sound represented by one or more ofthe plurality of channels that are associated with the different portionof the visual representation.
 27. The computer-implemented method ofclaim 25, wherein weighting each channel of the plurality of channels ofaudio data is performed repeatedly based on updated orientations of thevisual representation.
 28. The computer-implemented method of claim 21,wherein presenting the visual representation comprises displaying aglobe being one of a sphere or a polyhedron whose surface has aplurality of images wherein each image is a different portion of thevisual representation and represents a different predominant recordedsound that is represented by one or more of the plurality of channelsthat rae associated with the different portion.
 29. Thecomputer-implemented method of claim 21 wherein the listening positionrepresents a user location in a user interface.
 30. An audio processingcomputer system comprising a processor and memory having stored thereininstructions that configure the processor to: receive an audio objectencoded to preserve spatial characteristics of a plurality of recordedsounds, wherein the audio object comprises a plurality of channels ofaudio data representing the recorded sounds, each channel beingassociated with any one or more of a direction, a location, or a spatialdistribution; present a visual representation of the audio object,wherein the visual representation turns relative to a listeningposition; weight each channel of the plurality of channels of audio databased on an orientation of the visual representation, to emphasize thesound that is associated with the portion of the visual representationthat is oriented toward the listening position more than another soundassociated with a portion of the visual representation oriented awayfrom the listening position; and present sound based on the weightedchannels.
 31. The system of claim 30 wherein the memory has storedtherein instructions that when executed by 1 the processor present thevisual representation by displaying an image corresponding to theportion of the visual representation, the image representing apredominant recorded sound represented by one or more of the pluralityof channels, which are associated with the portion of the visualrepresentation.
 32. The system of claim 30, wherein presenting soundbased on the weighted channels simulates the sound as originating from alocation corresponding to the visual representation.
 33. The system ofclaim 32, wherein the memory has stored therein instructions that whenexecuted by the processor receive a user input to re-orient the visualrepresentation relative to the listening position so that a differentportion of the visual representation is visible from the listeningposition.
 34. The system of claim 33, wherein the different portion ofthe visual representation that is visible from the listening positionincludes an image representing a predominant recorded sound representedby one or more channels associated with the different portion of thevisual representation.
 35. The system of claim 33 wherein presenting thevisual representation comprises displaying a globe being one of a sphereor a polyhedron whose surface has a plurality of images wherein eachimage is a different portion of the visual representation and representsa different predominant recorded sound that is represented by one ormore channels associated with the different portion.
 36. The system ofclaim 33 wherein the listening position represents a user location in auser interface.
 37. The system of claim 36 wherein the memory has storedtherein instructions that when executed by the processor present thevisual representation by displaying an image corresponding to theportion of the visual representation, the image representing apredominant recorded sound represented by one or more of the pluralityof channels, which are associated with the portion of the visualrepresentation, and wherein the memory has stored therein instructionsthat when executed by the processor receive a user input to re-orientthe visual representation relative to the listening position so that adifferent portion of the visual representation is visible from thelistening position.
 38. The system of claim 37, wherein the differentportion of the visual representation that is visible to a user includesanother image representing a predominant recorded sound represented byone or more channels associated with the different portion of the visualrepresentation.
 39. The system of claim 38 wherein presenting the visualrepresentation comprises displaying a globe being one of a sphere or apolyhedron whose surface has a plurality of images wherein each image isa different portion of the visual representation and represents adifferent predominant recorded sound that is represented by one or morechannels associated with the different portion.
 40. The system of claim30 wherein the listening position represents a user location in a userinterface.